The use of refrigeration to prolong the life of food is an age old practice – one that continues to evolve in the 21st Century supply chain. Paleolithic hunters were known to preserve their catch in icy caves. In ancient times, ice was harvested and stored in China and other countries to support food storage. The Hebrews, Greeks, and Romans stockpiled snow in storage pits. They covered it with insulating material to help it last longer. Likewise, storage cellars have been used for centuries to keep foodstuffs cold.
In the late 18th Century, ice began to be first harvested commercially in the U.S. Techniques emerged for better insulating ice reserves, as well as for cutting uniform blocks of ice. Nathaniel Wyeth, one of the ice pioneers, "devised a method of quickly and cheaply cutting uniform blocks of ice that transformed the ice industry, making it possible to speed handling techniques in storage, transportation and distribution with less waste." Then, as with RPCs today, standardization of sizes facilitated supply chain operating efficiencies.
The "ice revolution" had begun. There were 35 commercial ice plants operating in the U.S. in 1879, a number which exploded to 2,000 by 1909. For a time, no pond was safe from ice cutters. Refrigeration made possible by ice was essential for the growth of the perishable goods trade. In 1850, for example, ice was used to chill a shipment of apples sent by ship from New England to California. As population and industrialization grew, however, water bodies were becoming fouled with sewage and other contaminants. Natural ice increasingly became a health issue, and the shift to mechanical refrigeration and artificial ice making began in earnest.
In the cold chain of the 21st Century, the basic premise of refrigeration still holds true. Consistent temperature management is critical to delaying product deterioration and ensuring product quality. Any incidence of temperature abuse in the extended supply chain will reduce quality, and the effects of multiple temperature issues are cumulative.
Temperature management begins with effective pre-cooling to remove field heat. Prompt pre-cooling lowers the rate of respiration and inhibits microorganism growth. It reduces enzymatic and respiratory activity while decreasing water loss and ethylene production. Indeed, delays associated with pre-cooling have a more profound impact on shelf life and quality than almost any other factor.
RPC ventilation also promotes air circulation in transport as well as at the distribution center and retail, enabling product to more readily hold temperature. It arrives at retail in better condition, and with a longer shelf life.
Natural ice, and later the ice revolution, marked important passages in the history of food storage before the development of mechanical refrigeration. With the emergence of RPCs and their role in further reducing food waste, a new revolution is now underway. It is a story you can help write.